The following account of the prior art relates to one of the areas of application of the present application, hearing aids.
When not accustomed to communicate with hearing impaired listeners, people struggle with how they should preferably speak when they are not familiar with signs that indicate hearing difficulties, and therefore it is very difficult for them to assess whether the way they speak benefits the hearing impaired.
Listening devices for compensating a hearing impairment (e.g. a hearing instrument) or for being worn in difficult listening situations (e.g. a hearing protection device) do not in general display the quality of the signal that reaches the listening device or display the quality of the wearer's speech reception to the wearer or to those people that the wearer communicates with.
Consequently it is difficult for communication partners to adapt their communication with a wearer of listening device(s) in a given situation, without discussing the communication quality explicitly.
A state of the art hearing instrument processes the incoming audio signal based on audiological data such as audiogram data, occlusion sensitivity and perhaps cognitive skills. The signal processing is typically determined by a number of processing algorithms such as compression, noise reduction, digital feedback cancellation in a manner determined once and for all according to these audiological input data. Hence, the processing may depend on the level in different acoustic frequency bands and to some extent on the sound environment (exemplified by the presence of a human voice, of wind noise, etc.) but not on the interaction effects between for instance the spectral content of the voice signal present at a given time and the prevailing wind or background noise.
US 2007/147641 A1 describes a hearing system comprising a hearing device for stimulation of a user's hearing, an audio signal transmitter, an audio signal receiver unit adapted to establish a wireless link for transmission of audio signals from the audio signal transmitter to the audio signal receiver unit, the audio signal receiver unit being connected to or integrated within the hearing device for providing the audio signals as input to the hearing device. The system is adapted—upon request—to wirelessly transmit a status information signal containing data regarding a status of at least one of the wireless audio signal link and the receiver unit, and comprises means for receiving and displaying status information derived from the status information signal to a person other than said user of the hearing device.
US 2008/036574 A1 describes a class room or education system where a wireless signal is transmitted from a transmitter to a group of wireless receivers and whereby the wireless signal is received at each wireless receiver and converted to an audio signal which is served at each wearer of a wireless receiver in a form perceivable as sound. The system is configured to provide that each wireless receiver intermittently flashes a visual indicator, when a wireless signal is received. Thereby an indication that the wirelessly transmitted signal is actually received by a given wireless receiver is conveyed to a teacher or another person other than the wearer of the wireless receiver.
Both documents describe examples where a listening device measures the quality of a signal received via a wireless link, and issues an indication signal related to the received signal.
EP2023668A2 describes a hearing device comprising a perceptive model implemented in a signal processing unit. A psychoacoustic variable related to an output signal to the user from the hearing aid, such as the loudness of the output signal, as determined by the perceptive model is transmitted to a remote control for visualization to allow a caring person to evaluate the cognition of the wearer of the output signal from the hearing device.
WO2012152323A1 relates to public address systems or other systems for emitting audio signals, like music, speech or announcements, in different locations like supermarkets, schools, universities, auditoriums. WO2012152323A1 describes a system for emitting and especially controlling an audio signal in an environment using an objective intelligibility measure. The system comprises an analyzing module for analyzing an acoustic signal from the environment and for providing an intelligibility measure from an objective intelligibility measure method, whereby the intelligibility measure is used as a feedback signal. The feedback signal may for example be coupled back to the system in order to improve or control the intelligibility of the acoustic signal.